Source of: /manual/en/function.dns-get-record.php
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<div id="function.dns-get-record" class="refentry">
<div class="refnamediv">
<h1 class="refname">dns_get_record</h1>
<p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">dns_get_record</span> — <span class="dc-title">Fetch DNS Resource Records associated with a hostname</span></p>
</div>
<a name="function.dns-get-record.description"></a><div class="refsect1 description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><b>dns_get_record</b></span>
( <span class="methodparam"><span class="type">string</span> <tt class="parameter">$hostname</tt></span>
[, <span class="methodparam"><span class="type">int</span> <tt class="parameter">$type</tt><span class="initializer"> = DNS_ANY</span></span>
[, <span class="methodparam"><span class="type">array</span> <tt class="parameter reference">&$authns</tt></span>
[, <span class="methodparam"><span class="type">array</span> <tt class="parameter reference">&$addtl</tt></span>
]]] )</div>
<p class="para rdfs-comment">
Fetch DNS Resource Records associated with the given
<i><tt class="parameter">hostname</tt></i>
.
</p>
</div>
<a name="function.dns-get-record.parameters"></a><div class="refsect1 parameters">
<h3 class="title">Parameters</h3>
<p class="para">
</p><dl>
<dt class="varlistentry">
<span class="term"><i><tt class="parameter">hostname</tt></i>
</span>
</dt><dd class="listitem">
<p class="para">
<i><tt class="parameter">hostname</tt></i>
should be a valid DNS hostname such
as "<i>www.example.com</i>". Reverse lookups can be generated
using <i>in-addr.arpa</i> notation, but
<a href="function.gethostbyaddr.php" class="function">gethostbyaddr()</a> is more suitable for
the majority of reverse lookups.
</p>
<blockquote><p><b class="note">Note</b>:
Per DNS standards, email addresses are given in <i>user.host</i> format (for
example: <i>hostmaster.example.com</i> as opposed to <i>hostmaster@example.com</i>),
be sure to check this value and modify if necessary before using it
with a functions such as <a href="function.mail.php" class="function">mail()</a>.
<br />
</p></blockquote>
</dd>
<dt class="varlistentry">
<span class="term"><i><tt class="parameter">type</tt></i>
</span>
</dt><dd class="listitem">
<p class="para">
By default, <b>dns_get_record()</b> will search for any
resource records associated with <i><tt class="parameter">hostname</tt></i>
.
To limit the query, specify the optional <i><tt class="parameter">type</tt></i>
parameter. May be any one of the following:
<b><tt class="constant">DNS_A</tt></b>, <b><tt class="constant">DNS_CNAME</tt></b>,
<b><tt class="constant">DNS_HINFO</tt></b>, <b><tt class="constant">DNS_MX</tt></b>,
<b><tt class="constant">DNS_NS</tt></b>, <b><tt class="constant">DNS_PTR</tt></b>,
<b><tt class="constant">DNS_SOA</tt></b>, <b><tt class="constant">DNS_TXT</tt></b>,
<b><tt class="constant">DNS_AAAA</tt></b>, <b><tt class="constant">DNS_SRV</tt></b>,
<b><tt class="constant">DNS_NAPTR</tt></b>, <b><tt class="constant">DNS_A6</tt></b>,
<b><tt class="constant">DNS_ALL</tt></b> or <b><tt class="constant">DNS_ANY</tt></b>.
The default is <em class="emphasis">DNS_ANY</em>.
</p>
<blockquote><p><b class="note">Note</b>:
Because of eccentricities in the performance of libresolv
between platforms, <b><tt class="constant">DNS_ANY</tt></b> will not
always return every record, the slower <b><tt class="constant">DNS_ALL</tt></b>
will collect all records more reliably.
<br />
</p></blockquote>
</dd>
<dt class="varlistentry">
<span class="term"><i><tt class="parameter">authns</tt></i>
</span>
</dt><dd class="listitem">
<p class="para">
Passed by reference and, if given, will be populated with Resource
Records for the <em class="emphasis">Authoritative Name Servers</em>.
</p>
</dd>
<dt class="varlistentry">
<span class="term"><i><tt class="parameter">addtl</tt></i>
</span>
</dt><dd class="listitem">
<p class="para">
Passed by reference and, if given, will be populated with any
<em class="emphasis">Additional Records</em>.
</p>
</dd>
</dl>
<p>
</p>
</div>
<a name="function.dns-get-record.returnvalues"></a><div class="refsect1 returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
This function returns an array of associative arrays. Each associative array contains
<em class="emphasis">at minimum</em> the following keys:
</p><table class="doctable table">
<caption><b>Basic DNS attributes</b></caption>
<thead valign="middle">
<tr valign="middle">
<th>Attribute</th>
<th>Meaning</th>
</tr>
</thead>
<tbody valign="middle" class="tbody">
<tr valign="middle">
<td align="left">host</td>
<td align="left">
The record in the DNS namespace to which the rest of the associated data refers.
</td>
</tr>
<tr valign="middle">
<td align="left">class</td>
<td align="left">
<b>dns_get_record()</b> only returns Internet class records and as
such this parameter will always return <i>IN</i>.
</td>
</tr>
<tr valign="middle">
<td align="left">type</td>
<td align="left">
String containing the record type. Additional attributes will also be contained
in the resulting array dependant on the value of type. See table below.
</td>
</tr>
<tr valign="middle">
<td align="left">ttl</td>
<td align="left">
<i>"Time To Live"</i> remaining for this record. This will <em class="emphasis">not</em> equal
the record's original ttl, but will rather equal the original ttl minus whatever
length of time has passed since the authoritative name server was queried.
</td>
</tr>
</tbody>
</table>
<p>
</p>
<p class="para">
</p><table class="doctable table">
<caption><b>Other keys in associative arrays dependant on 'type'</b></caption>
<thead valign="middle">
<tr valign="middle">
<th>Type</th>
<th>Extra Columns</th>
</tr>
</thead>
<tbody valign="middle" class="tbody">
<tr valign="middle">
<td align="left"><i>A</i></td>
<td align="left">
<i>ip</i>: An IPv4 addresses in dotted decimal notation.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>MX</i></td>
<td align="left">
<i>pri</i>: Priority of mail exchanger.
Lower numbers indicate greater priority.
<i>target</i>: FQDN of the mail exchanger.
See also <a href="function.dns-get-mx.php" class="function">dns_get_mx()</a>.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>CNAME</i></td>
<td align="left">
<i>target</i>: FQDN of location in DNS namespace to which
the record is aliased.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>NS</i></td>
<td align="left">
<i>target</i>: FQDN of the name server which is authoritative
for this hostname.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>PTR</i></td>
<td align="left">
<i>target</i>: Location within the DNS namespace to which
this record points.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>TXT</i></td>
<td align="left">
<i>txt</i>: Arbitrary string data associated with this record.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>HINFO</i></td>
<td align="left">
<i>cpu</i>: IANA number designating the CPU of the machine
referenced by this record.
<i>os</i>: IANA number designating the Operating System on
the machine referenced by this record.
See IANA's <a href="http://www.iana.org/assignments/operating-system-names" class="link external">» <i>Operating System
Names</i></a> for the meaning of these values.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>SOA</i></td>
<td align="left">
<i>mname</i>: FQDN of the machine from which the resource
records originated.
<i>rname</i>: Email address of the administrative contain
for this domain.
<i>serial</i>: Serial # of this revision of the requested
domain.
<i>refresh</i>: Refresh interval (seconds) secondary name
servers should use when updating remote copies of this domain.
<i>retry</i>: Length of time (seconds) to wait after a
failed refresh before making a second attempt.
<i>expire</i>: Maximum length of time (seconds) a secondary
DNS server should retain remote copies of the zone data without a
successful refresh before discarding.
<i>minimum-ttl</i>: Minimum length of time (seconds) a
client can continue to use a DNS resolution before it should request
a new resolution from the server. Can be overridden by individual
resource records.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>AAAA</i></td>
<td align="left">
<i>ipv6</i>: IPv6 address
</td>
</tr>
<tr valign="middle">
<td align="left"><i>A6</i>(PHP >= 5.1.0)</td>
<td align="left">
<i>masklen</i>: Length (in bits) to inherit from the target
specified by <i><tt class="parameter">chain</tt></i>
.
<i>ipv6</i>: Address for this specific record to merge with
<i><tt class="parameter">chain</tt></i>
.
<i>chain</i>: Parent record to merge with
<i><tt class="parameter">ipv6</tt></i>
data.
</td>
</tr>
<tr valign="middle">
<td align="left"><i>SRV</i></td>
<td align="left">
<i>pri</i>: (Priority) lowest priorities should be used first.
<i>weight</i>: Ranking to weight which of commonly prioritized
<i><tt class="parameter">targets</tt></i>
should be chosen at random.
<i>target</i> and <i>port</i>: hostname and port
where the requested service can be found.
For additional information see: <a href="http://www.faqs.org/rfcs/rfc2782" class="link external">» RFC 2782</a>
</td>
</tr>
<tr valign="middle">
<td align="left"><i>NAPTR</i></td>
<td align="left">
<i>order</i> and <i>pref</i>: Equivalent to
<i><tt class="parameter">pri</tt></i>
and <i><tt class="parameter">weight</tt></i>
above.
<i>flags</i>, <i>services</i>, <i>regex</i>,
and <i>replacement</i>: Parameters as defined by
<a href="http://www.faqs.org/rfcs/rfc2915" class="link external">» RFC 2915</a>.
</td>
</tr>
</tbody>
</table>
<p>
</p>
</div>
<a name="function.dns-get-record.changelog"></a><div class="refsect1 changelog">
<h3 class="title">Changelog</h3>
<p class="para">
</p><table class="doctable informaltable">
<thead valign="middle">
<tr valign="middle">
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody valign="middle" class="tbody">
<tr valign="middle">
<td align="left">5.3.0</td>
<td align="left">
This function is now available on Windows platforms.
</td>
</tr>
</tbody>
</table>
<p>
</p>
</div>
<a name="function.dns-get-record.examples"></a><div class="refsect1 examples">
<h3 class="title">Examples</h3>
<p class="para">
</p><div class="example">
<p><b>Example #1 Using <b>dns_get_record()</b></b></p>
<div class="example-contents programlisting">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$result </span><span style="color: #007700">= </span><span style="color: #0000BB">dns_get_record</span><span style="color: #007700">(</span><span style="color: #DD0000">"php.net"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents para"><p>The above example will output
something similar to:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Array
(
[0] => Array
(
[host] => php.net
[type] => MX
[pri] => 5
[target] => pair2.php.net
[class] => IN
[ttl] => 6765
)
[1] => Array
(
[host] => php.net
[type] => A
[ip] => 64.246.30.37
[class] => IN
[ttl] => 8125
)
)
</pre></div>
</div>
</div><p>
</p><div class="example">
<p><b>Example #2 Using <b>dns_get_record()</b> and DNS_ANY</b></p>
<div class="example-contents para"><p>
Since it's very common to want the IP address of a mail server
once the MX record has been resolved, <b>dns_get_record()</b>
also returns an array in <i><tt class="parameter">addtl</tt></i>
which
contains associate records. <i><tt class="parameter">authns</tt></i>
is returned as well containing a list of authoritative name
servers.
</p></div>
<div class="example-contents programlisting">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* Request "ANY" record for php.net,<br /> and create $authns and $addtl arrays<br /> containing list of name servers and<br /> any additional records which go with<br /> them */<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">dns_get_record</span><span style="color: #007700">(</span><span style="color: #DD0000">"php.net"</span><span style="color: #007700">, </span><span style="color: #0000BB">DNS_ANY</span><span style="color: #007700">, </span><span style="color: #0000BB">$authns</span><span style="color: #007700">, </span><span style="color: #0000BB">$addtl</span><span style="color: #007700">);<br />echo </span><span style="color: #DD0000">"Result = "</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />echo </span><span style="color: #DD0000">"Auth NS = "</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$authns</span><span style="color: #007700">);<br />echo </span><span style="color: #DD0000">"Additional = "</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$addtl</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents para"><p>The above example will output
something similar to:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Result = Array
(
[0] => Array
(
[host] => php.net
[type] => MX
[pri] => 5
[target] => pair2.php.net
[class] => IN
[ttl] => 6765
)
[1] => Array
(
[host] => php.net
[type] => A
[ip] => 64.246.30.37
[class] => IN
[ttl] => 8125
)
)
Auth NS = Array
(
[0] => Array
(
[host] => php.net
[type] => NS
[target] => remote1.easydns.com
[class] => IN
[ttl] => 10722
)
[1] => Array
(
[host] => php.net
[type] => NS
[target] => remote2.easydns.com
[class] => IN
[ttl] => 10722
)
[2] => Array
(
[host] => php.net
[type] => NS
[target] => ns1.easydns.com
[class] => IN
[ttl] => 10722
)
[3] => Array
(
[host] => php.net
[type] => NS
[target] => ns2.easydns.com
[class] => IN
[ttl] => 10722
)
)
Additional = Array
(
[0] => Array
(
[host] => pair2.php.net
[type] => A
[ip] => 216.92.131.5
[class] => IN
[ttl] => 6766
)
[1] => Array
(
[host] => remote1.easydns.com
[type] => A
[ip] => 64.39.29.212
[class] => IN
[ttl] => 100384
)
[2] => Array
(
[host] => remote2.easydns.com
[type] => A
[ip] => 212.100.224.80
[class] => IN
[ttl] => 81241
)
[3] => Array
(
[host] => ns1.easydns.com
[type] => A
[ip] => 216.220.40.243
[class] => IN
[ttl] => 81241
)
[4] => Array
(
[host] => ns2.easydns.com
[type] => A
[ip] => 216.220.40.244
[class] => IN
[ttl] => 81241
)
)
</pre></div>
</div>
</div><p>
</p>
</div>
<a name="function.dns-get-record.notes"></a><div class="refsect1 notes">
<h3 class="title">Notes</h3>
<blockquote><p><b class="note">Note</b>:
For compatibility with versions before this function was implemented
on such platforms as Windows, *BSD and MAC. Try the
<a href="http://pear.php.net/" class="link external">» PEAR</a> class
<a href="http://pear.php.net/package/Net_DNS" class="link external">» Net_DNS</a>.
<br />
</p></blockquote>
</div>
<a name="function.dns-get-record.seealso"></a><div class="refsect1 seealso">
<h3 class="title">See Also</h3>
<p class="para">
</p><ul class="simplelist">
<li class="member"><a href="function.dns-get-mx.php" class="function" rel="rdfs-seeAlso">dns_get_mx()</a> - Alias of getmxrr</li>
<li class="member"><a href="function.dns-check-record.php" class="function" rel="rdfs-seeAlso">dns_check_record()</a> - Alias of checkdnsrr</li>
</ul><p>
</p>
</div>
</div><?php manual_footer(); ?>
